The homologation, hydroformylation and carbonylation reactions of methanol to produce carbon oxygenates are well documented.
The homologation reaction is exemplified by the reaction of methanol with synthesis gas (a mixture of carbon monoxide and hydrogen) to produce ethanol namely: EQU CH.sub.3 OH+CO+2H.sub.2 .fwdarw.CH.sub.3 CH.sub.2 OH+H.sub.2 O
The reaction typically is conducted in the presence of a CO/Ru--I catalyst, at elevated temperatures and pressures (up to 10,000 p.s.i.g.).
However, in U.S. Pat. No. 4,727,200 there is disclosed an alcohol homologation reaction wherein methanol is reacted with synthesis gas in contact with a rhodium/ruthenium, iodine, diphosphine catalyst system.
The hydroformylation (or reductive carbonylation) reaction is exemplified by the reaction of methanol with synthesis gas to form acetaldehyde: EQU CH.sub.3 OH+CO+H.sub.2 .fwdarw.CH.sub.3 CHO+H.sub.2 O
Typically, a Co--I or Rh--I--PR.sub.3 catalyst is utilized, again at elevated temperatures and pressures.
Tertiary polyphosphine monoxide ligands are used in the hydroformylation processes described in the following patents: ##STR1##
Additionally, the use of phosphite ligands in hydroformylation processes is taught in the followings patents: ##STR2##
Further hydroformylation processes using sulphonated tertiary phosphine ligands are described in U.S. Pat. Nos. 4,716,250 and 4,731,486.
The carbonylation reaction is exemplified by the reaction of methanol with carbon monoxide to form acetic acid or methyl acetate, depending on the solvent used. ##STR3##
In U.S. Pat. No. 3,769,329, issued to F. E. Paulik et. al. there is disclosed a carbonylation process which comprises reacting methanol with carbon monoxide at 175.degree. C. and 1000 p.s.i.g. to form acetic acid. This process is illustrative of existing industrial conditions for conducting the reaction.
U.S. Pat. No. 4,670,570, issued to Wegman et. al. details a process for the production of carboxylic acids from alcohols using rhodium complex catalysts.
More specifically, the catalyst comprises: EQU Rh(CO)X(R'R"PGZ)
wherein
Z is selected from the group consisting of: ##STR4## and G represents one of the following two groups: ##STR5##
The Wegman reaction conditions are mild, typically involving reaction temperatures less than about 130.degree. C. and a reaction pressure less than about 250 p.s.i.g.